OBJECTIVE: To define interactions of molecular chaperones which can serve as targets for AIDS or cancer therapies. RESULTS Preliminary data indicate that molecular chaperones are involved both in the assembly of HIV particles and in influencing the antigenic make-up of normal and malignant cells. This makes them suitable targets for therapeutic interventions. To address these issues, we generated stable transfectans expressing two distinct molecular chaperone families, namely Hsp60 and Hsp70. We focused on structural analyses of the Hsp molecule regions responsible for various biological effects. We found that stably transfected clones of the B16 melanoma, which constitutively express human Hsp72, exhibit significantly increased levels of MHC class I antigens on their surface. This Hsp72-mediated upregulation of surface MHC class I antigen represents an increase in the amount of functional MHC-peptide complexes as measured by conformation-dependent antibodies and recog-nition by MHC class I-restricted CTL. The hsp72 gene has been mutagenized and a number of mu-tans lacking variable parts of the molecule at the carboxy or amino ends or in the middle of the mo-lecule have been generated and transfected into B16 melanoma cells. We are performing detailed studies to define the functionality of different parts of the Hsp72 molecule. Similar studies have be-gun with the Hsp60 molecule. Our earlier studies defined that the suitable expres-sion of Hsp72 or Hsp60 can overcome a defect in MHC class I expression and antigen presentation often associated with malignant transformation. The analysis of this mechanism using site-directed mutagenesis will likely generate data useful for developing novel gene therapies for cancer and viral diseases. We have applied through WARF for international and US patents ("Immune response enhancer therapy") for our crucial discoveries in this area. In 1997, we gained a patent, with Prof. D. Rich from the Dept. of Pharmacy, covering our previous discoveries on using molecular chaperones in immuostimulation. FUTURE DIRECTIONS In 1998, we plan to continue with our analyses utilizing the site-directed mutagenesis and to initiate experiments evaluating the role of Hsps in the virus (HIV/SIV) assembly. KEY WORDS Hsp60, Hsp70, melanoma